Theodore r



Nov. 11, 1958` T. R. RosENBERG APPARATUS FOR PRODUCING STEREOSCOPICFLUOROSCOPIC IMAGES 2 Sheets-Sheet 1 Filed April 19, 1957 1 H I I I I II I I. Ill I I I I I I 1 I I I I I l I THEoDoRE R. rosENBERG INVENTOR.

BY W

AGENT Nov. 11, 1958 T. R. RosENBERG APFARATUS FOR PRODUCING STEREOSCOPICFLUOROSCOPIC IMAGE'S 2 sheets-shee Filed April 19, 1957 THEoDoRE R.RosENBERG INVENTOR.

AGENT 2,860,25 3 Patented Nov. 11, 1958 APPARATUS FOR PRDUCINGSTEREOSCOPIC FLUOROSCOPIC IMAGES Theodore R. Rosenberg, Jackson Heights,N. Y. Applicafin April 19, 1957, serial No. 653,832

6 Claims. (Cl. 250-60) My present invention relates to apparatus forviewing objects by means of X-rays in such manner as to produce shadowimages in stereoscopic relief on a fluorescent screen.

In the production of such images it is known to utilize two spaced-apartpoint sources of X-rays whose rays impinge at different angles upon acommon screen by way of an object to be fluoroscoped, along with twosynchronized rotating shutters for alternately obstructing these sourcesand simultaneously shielding the screen from alternately the right andthe left eye of the Viewer. Heretofore, difficulties have beenencountered in precisely synchronizing the two shutters, especiallywhere a certain adjustability between the viewer's eyepiece and thescreen was desired. Thus, if a flexible shaft is used to drive theshutter of the eyepiece, a displacement of the latter relative to thestationary frame of the apparatus will generally vary, to some degree,the twist in the shaft "so that the relative phasing of the two shuttersis changed, with consequent blurring of the image.

In my U. S. Patent No. 2,537,373, issued January 9, 1951, I havedisclosed an extendible bellows for X-ray apparatus which thefiuoroscopist may use for the purpose of observing a projected image ona viewing screen, at different angles and from different distances,without being disturbed by outside light. An important object of thepresent invention is to provide a stereoscopic X-ray apparatus whereinthe front shutter, i. e. the one located between the eyepiece and thescreen, is received in a bellows of this description in such manner asto enable accurate synchronization in the various viewing positions. Amore specific object, allied with the preceding one, is to provide abellows-type viewing attachment for stereoscopic X-ray apparatus which,in addition to being adjnstable for synchronization purposes, is ofsimple and light-weight construction so as to be convenientlysupportable by the head of the user essentially in the same manner as isthe bellows of my aforesaid prior patent.

In a broader Sense, it is an object of my invention to provide means foradjustably interconnecting two rotating shutters, through theintermediary of a flexible shaft, in such manner as to enable readycompensation for deviations from a predetermined phase relationship dueto variations in the relative positioning of the shutters or to othercauses.

Furthermore, notwithstanding accurate synchronization of the twoshutters, the image observed by a particular Viewer on the screen of astereoscopic X-ray apparatus may be unsatisfactory because of thecorrelation existing between the disalignrnent of the two projectedX-ray images and the spacing of the viewers eyes, this latter spacingvarying among difierent individuals. It is, therefore, a further objectof my present invention to provide simple and conveniently operablemeans for varying the disalignment of the projected images in anapparatus of the character referred to.

Thus, one of Ithe features of my invention resides in the provision of asource of two adjustably intersecting X-ray beams comprising asubstantially sealed casing, preferably filled with insulating oil,containing a pair of X-ray tubes positioned side by side and rotatableor otherwise displaceable relatively to each other by means of a controlmechanism having an Operating member,

such as a knob, projecting from the casing By way of` two suitablypositioned windows (which, if desired, could be combined into a singlewindow) the rays emanating from the two tubes are adjustably directedupon a receiving surface, such as a fiuorescent viewing screen.

According to another feature of the invention, there is providedforwardly of a fluorescent screen an expandible bellows equipped with aneyepiece and, behind the latter, with a rotatable shutter driven by afiexible shaft, the coupling between the shaft and the shutter includinga sun gear and, rotatable about it and in mesh therewith,

a planet gear whose movement about the sun gear in one sense or theother, brought about by `an adjustable actuating member, advances orretards the phase of the rotating shutter with respect to a drivingelement connected with the other end of the fiexible shaft. In aparticularly simple and advantageous arrangement the sun gear and theplanet gear are a pair of bevel gears Vdisposed in an elbow-shapedsupporting member, the shaft of the first bevel gear being coupled atone end of the elbow to the shutter shaft, the shaft of the second bevelgear being coupled at the other end of the elbow to the flexible shaft.The driving element is preferably coupled in a positive manner, througha mechanical linkage, with a second rotatable shutter interposed betweenthe screen and the source of the two X-ray beams, although it is to beunderstood that the invention, at least .in its broader aspects, is alsoapplicable to systems in which the beams are alternately triggered onand ofi electrically, as is well known per se.

The above and other objects and features of my invention will be morefully apparent from the following detailed description, reference beinghad to the accompanying drawing in which:

Fig. 1 is a side-elevational view of an bodying the invention;

Fig. 2 is a front-elevational view, drawn to a larger scale, of themechanism for driving the rear shutter inserted between the beam sourceand the screen in the apparatus of Fig. 1;

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2;

Fig. 4 is a sectional view taken on the line 4-4 of Fig. 2;

Fig. 5 is a front-elevational view` of the eyepiece forming part of theapparatus of Fig. 1;

Fig. 6 is a fragmentary sectional view taken on the line 6 6 of Fig. 5;

Fig. 7 is a view taken on the line 7-7 of Fig. 6;

Fig. 8 is a fragmentary bottom view taken on the line 8-8 of Fig. 6; and

Fig. 9 is a somewhat diagrammatic view of the coupling mechanism linkingthe mechanism of Fig. 2 with the front shutter located behind theeyepiece of Fig. 5,.

The apparatus shown in the drawing comprises a base 10 from which risetwo pairs of standards 11, 12 (only one visible). Secured to thesestandards, at a suitable elevation above ground, is the fiuoroscopicunit 13 whose Vertical and horizontal position on the standards may beadjusted by well-known means not shown and which is balanced by acounterweight (not shown) inside standard 11 via a chain 14 passingaround a pulley 15.

The unit 13 includes a diaphragm frame 16, a tube housing 17 hingedlysecured to this frame, and a viewing assembly 18 attached to the frameby means of an arm 19 on which this assembly is swingably or slidablymounted so as to aford variable spacing between a fluorescent apparatusemscreen 21 and the diaphragm whose horizontal and vertical maskingstrips 20 may be moved inwardly or outwardly in a manner not furtherillustrated; screen 21 forms the rear surface of assembly 18.

Mounted on the tube housing 17, by means of a hracket 22, is a motor 23energized via leads 24 from a control panel 25 on standard 12. Otherleads 26 extend from this panel to a pair of conventonal X-ray tubes 27,28 rotatably mounted on a support 29 within housing 17. Each of thesetubes is provided with a cathode 30 and an anode 3-1, as seen in Fig. 3,and has in its envelope a port 32 transparent to radiation which isaligned with a respective window 33, 34 (Figs. 2 and 3) in the frontcover of the housing and in an additional lead shield 35 externallysecured to this cover. The housing 17 is filled with an insulating oil36.

i Rigid with the tubes 27, 28 are a pair of gears 37, 3.8, respectively,which mesh with each other and serve to adjust the angular position andthe effective spacing of these tubes under the control of a knob 39positioned outside housing 17. Knob 39 is attached to a rod 40 whichcarries a pinion 41 meshing with gear 38. It will` be apparent thatrotation of knob 39 turns the two tubes in opposite directions, aboutaxes which are offset from thetube axes. thereby varying the angle ofintersection` and the relative dstance of the beams emitted throughWindows 33, 34. The effective cross-section of these beams can be variedby manoulation of the diaphragm strips 20 when the housing 17 has beenswung from its ino'nerative position (Fig. 2) into its operativeposit-ion (Fig. 1). The path of the beams also passes through a rearshutter 42, in the form of a rotatable disk of a material opaque toX-rays (such as lead.) having an arcuate cutout 43. which is positivelycoupled with motor 23 through a chain 44 engaging a sprocket 4,5, ondisk shaft 46 and a sprocket 47 on motor shaft 48. Disk 42 is balancedby the provision of an arcuate flange 42' adjacent its cutout 43.

The motor shaft 48 is also connected to a flexible shaft 49, surroundedby a sheath 50, which leads toward front end of a flexible bellows 51extending forwardly'from the fluorescent screen 21; bellows 51 maybelof. the construction described and claimed in my prior Patent No.2,537,373 referred to above. As best seen iniFigs.. 6 and 9, the otherend of flexible shaft 49 is coupled to a shaft- 52 carrying a bevel gear53 which meshes with another bevel gear 54 on a shaft 55, the two bevelgears and their shafts being rotatably disposed inside an elbow 56bodily swingable about the shaft 55. The latter shaft is coupled to anextension shaft 55' journaled in the walls of a chamber 57 secured tothe smaller, forward end of the frusto-pyramidal bellows 51.

On shaft 55' there is mounted, within chamber 57, a front shutter 58 inthe form of a rotatable disk, preferably of light-weight plasticmaterial, having an arcuate cutoutv 59. Disk 58 is positioned betweenthe large aligned apertures 60a, 60h provided in the rear wall ofchamber 57 and in the front wall of bellows 51, on the one hand, and themuch smaller viewing apertures 61a, 6117 in the front wall of thischamber to which is secured a rubber mask 62 constituting, along withthis apertured. front wall, the eyepiece of the instrument. At v63a, 63bthere are shown the extremities of astrap,

egrtending from the front wall of chamber 57 on oppositesides of mask62, which may be used to` attach the` eyepiece to the head of a Viewerin the manner illustrated in Fig. 1 of my above-identified prior patent.

The forward end of bellows 51 is constituted by a plastic frame 64 whosebottom plate is formed with an elongated slot 65 (Fig. 8) through whichpasses the sheath 50 of flexible shaft 49. Slidably mounted underneaththis bottom plate is apanel 66 having a hole traversed lby thesheathf50. The projectingportion of thevvsheath is straddled by thebifurcateend of a lever 67 which is pivoted to the underside of chamber57 by a stud 68, a spring 69 surrounding this stud so as to bearfrictionally upon the lever 67. As will be readily apparent from Figs. 8and 9, any displacement of the lever 67 against the frictionalresistance of spring 69 will Shift the sheath 50 laterally With respectto the axis of disk 58, thereby swinging the coupling elements withinelbow 56 about the shafts 55, 55' in line with this axis. Bevel gear 53,in mesh with bevel gear 54, thus causes this latter gear to rotate,together with shafts 55, 55' and disk 58, through an angle correspondingto the extent of the displacement of lever 67; this changes the relativeangular position of the cutouts 43, 59 on disks 42, 58,'respective1y, soas to enable correction of any phase displacement between the operativecycles of the two shutters.

In operation, a person to be fluoroscoped steps into the space betweenscreen 21 and diaphragm frame 16, or an object to be exarnined isintroduced into that space, whereupon a three-dimensional shadow picturewill be apparent to the viewer as a result of the alternate flashing ofdisaligned images upon screen 21 by the projection device 27, 28, 42.

It will be understood that lever 67 and panel 66 represent only anillustrative embodiment of a mechanism for revolving a planet gear, suchas the bevel gear 53, about a sun gear, such as the bevel gear 54, inthe coupling of a flexible shaft 49 and its extension 52 to a rigidshaft 55, 55' and that various modifications of this mechanism, as wellas of other elements described" hereinabove and illustrated in thedrawing, are possible without departing from the spirit and scope of theinvention as defined in the appended claims.

I claim:

1. In a stereoscopic viewing system, in combination, a rotatable shutterand mechanism for synchronously coupling said shutter with a source ofalternately projected images viewable through said shutter, saidmechanism comprising drive means including a rotatable element, a firstshaft having one end coupled with said element, a second shaft carryingsaid shutter, and adjustable coupling means between said second shaftand the other end of said first shaft including a sun, gear positivelycoupled with one of said shafts, a planet gear positively coupled withthe other of said shafts in mesh with said sun gear, and control meansfor revolving said planet gear about said sun gear.

2. In a stereoscopic viewing system, in combination,a rotatable shutterand mechanism for synchronously conpling said shutter with a source ofalternately projected images viewable through said shutter, saidmechanism comprising drive means including a rotatable element, aflexible shaft having one end coupled with said element, aplanet gear onthe other end of said fiexible shaft, a sun gear in mesh with saidplanet gear, means positively coupling said sun gear with said shutter,and control means for revolving said planet gear about said sun gear.

3. The combination according to claim 2, wherein said sunand planetgears are bevel gears.

4. In a fluoroscopic apparatus having a screen and projection means foralternately fiashing relatively disaligned X-ray images of an objectupon said screen, in combination, an extendible bellows mountedforwardly of said screen, an eyepiece at the-forward end of saidbellows, a rotatable shutter between said eyepiece and said screenadapted to` shield said screen alternately from the right and the lefteye of a viewer, a driving element rotatable in synchronism with thealternations of said source, a fiexible shaft having one end positivelycoupled with said driving element, a rigid shaft carrying said shutter,a first bevel gear on said rigid shaft, a secondbevel gear on the otherend of said fiexible shaft and in mesh with said first bevel gear, andadjusting means operable to revolve said second bevel gear about saidfirst bevel gear.

5. The combination accordingtoclaim, further com:

prising an albow-shaped coupling member having a first extremitycontaining an end of said rigid shaft and said first bevel gear as wellas a second extremity containing said other end of said flexible shaftand said second bevel gear, said coupling member being bodily swingableabout said rigid shaft by said adjusting means.

6. A stereoscopic viewing assembly for fluoroscopic apparatus,comprising a fiuorescent screen, projection means for alternatelyflashing relatively disaligned X-ray images of an object upon saidscreen, an extendible bellows mounted forwardly of said screen andhaving an eyepiece at its forward end, a rotatable shutter between saideyepiece and said screen adapted to Shield said screen alternately fromthe right and the left eye of a Viewer, and mechanism for synchronouslycoupling said first shutter with said projection means; said projectionmeans including a substantially sealed housing, a pair of X-ray tubesmounted inside said housing, and another rotatable shutter between saidhousing and said screen, said housng being provided with window meanspermitting passage of radiation from said tubes to the exterior; saidmechanism including a fiexible shaft linking said shutters with eachother, said other shutter being opaque to said radiation, and adjustablecoupling means between said flexible shaft and the first-mentionedshutter, said coupling means including a rigid shaft for saidfirst'mentioned shutter, a sun gear on said rigid shaft, a planet gearon said flexible shaft in mesh with said sun gear, and adjusting meansfor revolving said planet gear about said sun gear.

References Cited in the file of this patent UNITED STATES PATENTS1,995,054 Chambers Mar. 19, 1935 2,214,621 Leishman Sept. 10, 19402,537,373 Rosenberg Jan. 9, 1951

